This image from NASA's IRIS spacecraft shows the region around two sunspots - the dark areas at upper left and lower right. It shows emission from ionized silicon (Si IV) in the transition region at a temperature of about 116,000° Fahrenheit (64,000° Celsius), plus ultraviolet continuum from the chromosphere at a temperature of about 17,000°F (9,000°C). The bright dots are short-lived intense patches of Si IV emission. The role that these dynamic events have in heating the solar atmosphere is currently unknown. // NASA